Fluid pressure operated chuck



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A. E. CHURCH FLUID PRESSURE OPERATED CHUCK Filed May 3.5a 1947 INVENTOR l A CJRNEY Le Patented May 30, 1950 UNITED STATES ;EN.!` QFFICE FLUID PRESSURE OPRATED oriU'oK Application May 15, 1947, Serialivc 743,314

Claims. l

This invention relates to chucks and more particularly to chucks having their jaws actuated in closing or in closing and opening directions by means of air or other nuid pressure acting on a piston operatively connected to the jaws.

object of the present invention is to provide a powerful jaw closing mechanism for chucks which may be conveniently actuated by admit- 'ting liiid under pressure to an expansion member within the chck body or Within 'an actuating member therefor.

Another object of the invention is 'to provide a pressure tight exbansible member housed withn in the chuck body having means to admit uid such as air thereto, expansion of the member serving to actuate a 4piston within the chuck body in one direction, or to provide opposed e'xpansion members to actuate the piston in opposite directions.

And iinally it is an object of the invention to provide a bell-crank lever or wedge type connection between the jaws and the 'pistn so that a relatively long `traverse of the piston will "produce a relatively short but powerful movement of the jaws.

A feature of importance of the invention is that by admitting fluid under pressure to `one or the other of the opposed expansion members which preferably are of annular form, a centrally and axially movable piston within the chuckor an actuating member therefor is 'moved in one or the other direction and b`ell-cranliA levers or wedges, each operatively 'connected to the piston and connected to the jaws, are oscillated to 'radially actuate the j aws'.

Another 'feature of the invention is that a single expansible member may be employed to actuate the jaws in one direction and one or more springs acting on the piston may be used to actuate the jaws in the opposite direction. l

Another object of importance is that the jaw actuating levers such as bell-cranks or other form of levers, when the jaws moved thereby are in their Work clamping position, may be, `if desired, self-locking, so that failure of the uid pressure will not cause the jaws to open and release the work.

And finally it is a feature of importance that the jaw actuating bellcranks have the ends of their long arms in engagement with the central piston to be moved thereby, the short arms having their ends pivotally retained in fixed positions Within the chuck body, the intermediate portions of the bell-cranks being individually `onnected 2 by suitable pivotal means to the radially movable Jaws.

With the above and `other objects in View, the invention may include the features of construction and operation set forth in the following specification and illustrated in lthe accompany-1 ing drawings.

In the accompanying drawings annexed hereto and forming a part `of this specification, I have shown the invention embodied in 'several different forms of chucks but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining' or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Fis. `l is a central sectional view of the actuate ing means for a rotating type chuck having ex"- pansible members to which air or other fluid under pressure may be admitted to actuate the chuck jaws (not shown) in opposite directions.

Fig. 2 is a half sectional view of a rotatingr type 'of chuck having opposed eipansible members "for actuating the chuck jaws in opposite direction, and

Fig. 3 is an enlarged View 'of a portion of Fig. 2 showing a fluid admitting member adaptable for controlling the inflatng of one expansible member and the donating of the other.

In the above mentioned drawings there have been shown several embodiments of the invention which are new deemed preferable, out it is to be understood that changes 'and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly, and in its prf-erred aspect, the invention may include the fllowing principal parts: First, a body member having means mounting it for rotation `on a spindle or for operation in fixed position on a table -or other support; second, radially7 movable jaws siidable within the body member; third= a central axially 'movable piston within the body member; fourth, one or more expansible members of anni-lar form within the body member and in contact with a portion of the piston; fifth, means to admit air or other iuid iinder pressure to said member or rr'le'rnbers; and si-ath, bellecrank or other uns means connectingsaid Jaws and piston.-

R'eferring' now to' 1 of the drawings, it will be seen that the actuating head eil for arotatably mounted cliucii is "shown adaptable for any t'ype of chuck (not shown). The head ,portion is or preferably as shown in Fig. 3.

adapted for attachment to the tail end of a machine tool spindle for rotation therewith. The body member 5i) is hollow and within it slides a piston 52 attached to a central pull rod 54 by means of which a standard form of chuck mounted on the spindle may have its jaws actuated.

Within the body member 59 and disposed on opposite sides of the piston 52 are expansible members 55 of annular form. One of these members 55 is shown expanded and the other contracted. To admit fluid under pressure individually to these members 55 separate conduits 58 and 60 are provided leading from a supply connected into a member 52 ro tatably mounted relative to the body member 59. For this purpose the supply member 62 for the fluid is mounted on anti-friction bearings 64 supported on a central hub extension member 65 attached to the back plate 72 of the body member 59. As shown, the conduits 58 and 5U are provided in this hub extension member having lateral openings 58 and 1li for admitting the fluid from the supply. Exit openings for these conduits 58 and 60' lead to radially extending conduits forming parts of conduits 53 and @il within a back plate 'l2 forming part of the body member. From the peripheral ends of these radial conduits the fluid is admitted through suitable nipples 14 to the interior of the expansible members 55. As indicated in Fig. 1 two sources of supply of uid are shown each leading to one of the annular spaces I6 or 78 within the supply member 62. To form these separated supply chambers, sleeves 8B are secured in alined positions within this member 62. From the above description it will be seen that by suitable valves attached to the supply chambers 16 and 'ES iluid under pressure may be admitted to the interior of either of the expansible members 55. Piston 52 may therefore be actuated axially within the body member and the pull rod 54 for opening and closing the jaws of a chuck or other device will also be moved.

Referring to Fig. 2, a double acting chuck is partially shown. In this figure a body member 84, a part only of which is shown, is provided with .chuck jaws 86, one only of which is shown. Within the chuck body is a piston 8S generally similar to the piston shown in Fig. 1, Bell-cranks 99 have one end engaging an annular groove provided in the hub extension of the piston 84 and their opposite and shorter ends are engaged within a recess provided within plugs 92 iitted into va top plate formingY part of the body member.

Their intermediate portions are pivotally attached by cross pins 94 to the chuck jaws 85.

To actuate the piston 98, expansible impervious members 95 are provided, one disposed on either side of the piston S8. To admit air under pressure individually to these members 96 self-closing valve nipples 98 may be provided individually connected to suitable sources of fluid under pressure. In Fig. 3 is shown a detail View of the fluid admitting connections for the members 95.

lValve nipples 93 are provided with spring closed valves having their valve casings connected by suitable individual conduits to the members 9d. These conduits may be direct as shown in Fig. 2 In Fig. 3 is shown a iluid supply in the form of a flexible tube 99 having a self-closing valve Hit at its free end. A yoke member I! is attached to this end of the tube, the ends being spaced from the valve l!! and on opposite sides of the valve.

By applying the tube 99 with its valve Ill threaded plugs.

against one of the nipple valves 98, one of the inflatable members will be expanded. Simultaneously with the valve i60 being positioned against one of the nipple valves, an end of the yoke member projects into the other nipple valve and holds it in its open position. While fluid is being admitted to one expansib-le member 96, iiuid will be simultaneously exhausted from the other member @5. In either operative position of the tube 99 and valve lil!! the end of the yoke member opposite that entering a nipple 99 enters one oi the depressions m2 closed by suitable These depressions are formed the drilling to form the conduits from the nipple valves to the iniiatable members 96.

What claim is:

1. A chuck operating mechanism comprising a body member, having a plurality of jaws movable therein, a piston slidably mounted within said body member, an impervious, flexible and expe risible member on one side of said piston housed within said body member, means to admit fluid under pressure to within said member to move the piston, and bell-cranks having their arms connected respectively to said piston and body member and their intermediate portions pivotally connected to said jaws, whereby movement of said piston will actuate said jaws.

2. A chuck operating mechanism comprising a body member having movable jaws therein, a piston axially movable within said body member, means operatively connecting said piston and jaws, impervious, exible and expansible members disposed on opposite sides of said piston and housed within said body member, self-closing valves for said expansible members, and means attachable to said valves to simultaneously admit fluid under pressure to one oi said expansible and exhaust iiuid from the other expansible member, whereby said piston and jaws may be moved in opposite directions.

3. A chuck operating mechanism comprising a body member having movable jaws therein, a piston axially movable within said body member, means operatively connecting said piston and jaws, expansible and flexible pressure tight members disposed on opposite sides of said piston and housed within said body member, iiuid admitting valves for said expansible members, and means adapted to simultaneously open said valves, whereby fluid under pressure m-ay be admitted -to one expansible member and exhausted from the other, whereby said piston and jaws may be moved in opposite directions.

4. A chuck operating mechanism comprising a body member having movable jaws therein, a piston axially movable within said body member, levers operatively connecting said piston and jaws, expansible and flexible pressure tight members disposed on opposite sides of said piston and housed Within said body member, means to admit uid under pressure to one of said expansible members and exhaust fluid from the other member, whereby said piston and jaws may be moved in opposite directions, movement of the piston in one direction actuating said levers to a selflocking and work-clamping position.

5. A chuck operating mechanism comprising a body member having movable jaws therein, a piston axially movable within said body member, bell-crank levers operatively connecting said piston and jaws, expansibleand flexible pressure tight members disposed on opposite sides of said piston and housed within said body member, means detachable relative to said body member 5 to simultaneously admit fluid to one expansible member and permit exhaust of fiuid from the other member, whereby said piston and jaws may be moved in opposite directions, movement of the piston in one direction actuating said bellcrank levers to a self-locking and work-clamping position.

ALBERT E. CHURCH.

REFERENCES CITED The following references are of record in the le of this patent:

Number 6 UNITED STATES PATENTSy Name Date Oliver July 6, 1909 Elvers Feb. 14, 1922 Fornaca Jan, 4, 1927 Neidow Mar. 29, 1932 Dahlman Nov. 7, 1933 Bush Dec. 30, 1941 Hollerith Oct. i9, 1945 Keller Feb. 5, 1946 FOREIGN PATENTS Country Date Number France June 3, 1919 

